Over-voltage protection method and device

ABSTRACT

Embodiments of the present disclosure provide an over-voltage protection method, an over-voltage protection device and a display device. When the voltage value of the output signal is greater than the first preset voltage threshold, it is determined whether the voltage value of the output signal meets the preset over-voltage protection condition. If the voltage value of the output signal is detected to meet the preset over-voltage protection condition, the first control signal is output to stop output of the output signal or lower the voltage value of the output signal.

CROSS-REFERENCES TO RELATED APPLICATION

This application is the International Application No. PCT/CN2018/116844for entry into US national phase with an international filing date ofNov. 22, 2018 designating US, now pending, and claims priority toChinese Patent Application 201811102252.X, filed on Sep. 20, 2018, thecontent of which is incorporated herein by reference in its entirety.

BACKGROUND Field of the Invention

The embodiments of the present application relate to the field ofelectronic technologies, and in particular, to over-voltage protectionmethod, over-voltage protection device, and display device.

DESCRIPTION OF RELATED ART

The description herein are merely illustrative of the technicalbackground associated with the present disclosure and do not necessarilyconstitute prior art. In order to protect the back-end electroniccomponents from damage due to excessive output voltage, an over-voltageprotection mechanism is usually arranged at the voltage output terminal,so that the output voltage can be turned off when the output voltage istoo high. However, in the existing over-voltage protection, the voltageoutput is usually turned off after the output voltage exceeds thethreshold voltage, and the false shutdown due to external noiseinterference cannot be avoided, which greatly affects the stability ofthe back-end circuit.

For example, a display panel usually needs different power supplyvoltages according to various functions of the function circuits. Thesepower supply voltages may be provided by a power management chip. Inactual operation, the output voltage would be too high due to theinfluence of the outside environment or the load, if it is not protectedin time it will affect the normal display of the display panel or evenburn out the display panel. Therefore, the power management chip in thedisplay panel is usually provided with an over-voltage circuit. When theoutput voltage of the power management chip reaches the shutdownthreshold, the over-voltage protection is activated to turn off thevoltage output.

BRIEF SUMMARY OF THE INVENTION

In the existing over-voltage protection, the voltage output is usuallyturned off after the output voltage exceeds the threshold voltage, andthe false shutdown due to external noise interference cannot be avoided,which greatly affects the stability of the back-end circuit.

One object of the present disclosure is to provide an over-voltageprotection method achieving the purpose including, but not limited to,avoiding the false shutdown due to external noise interference andimproving the stability of the back-end circuit.

In an embodiment of the present disclosure, it is provided anover-voltage protection method, comprising:

determining whether a voltage value of an output signal is greater thana first preset voltage threshold;

detecting, within a present time range, whether the voltage value of theoutput signal meets a preset over-voltage protection condition in thecase that the voltage value of the output signal is greater than thefirst preset voltage threshold; and

outputting a first control signal to stop output of the output signal orto lower the voltage value of the output signal in the case that it isdetected, within the preset time range, that the voltage value of theoutput signal meets the preset over-voltage protection condition.

In an embodiment, the step of detecting, within a present time range,whether the voltage value of the output signal meets a presetover-voltage protection condition comprises:

dividing the preset time range into n counting cycles, where n is aninteger greater than 1;

determining whether the voltage value of the output signal in each ofthe counting cycles is greater than the first preset voltage threshold;and

determining that the voltage value of the output signal meets the presetover-voltage protection condition in the case that the voltage value ofthe output signal in each of the counting cycles is greater than thefirst preset voltage threshold.

In an embodiment, the step of detecting, within a present time range,whether the voltage value of the output signal meets a presetover-voltage protection condition comprises:

dividing the preset time range into n counting cycles, where n is aninteger greater than 1;

detecting whether the voltage value of the output signal is greater thanthe first preset voltage threshold in each of the counting cycles;

counting the counting cycles and outputting a count signal indicatingthe number of the counting cycles during which the voltage value of theoutput signal is greater than the first preset voltage threshold; and

determined that the voltage value of the output signal meets the presetover-voltage protection condition in the case that a value of the countsignal is greater than a preset over-voltage period threshold.

In an embodiment, the output signal is a voltage signal output from asignal output circuit, and the first control signal is furtherconfigured to control the signal output circuit to trigger anover-voltage protection operation.

In an embodiment, the over-voltage protection method further comprises:

receiving the output signal, and outputting a second control signal inthe case that the voltage value of the output signal is greater than orequal to a second preset voltage threshold to stop output of the outputsignal, wherein the second preset voltage threshold is greater than thefirst preset voltage threshold.

In an embodiment of the present disclosure, it is provided anover-voltage protection device, comprising:

a voltage comparison circuit configured to determine whether a voltagevalue of an output signal is greater than a first preset voltagethreshold;

a voltage detection circuit configured to detect, within a present timerange, whether the voltage value of the output signal meets a presetover-voltage protection condition in the case that the voltage value ofthe output signal is greater than the first preset voltage threshold;and

a control circuit configured to output a first control signal to stopoutput of the output signal or to lower the voltage value of the outputsignal in the case that it is detected, within the preset time range,that the voltage value of the output signal meets the presetover-voltage protection condition.

In an embodiment, the voltage detection circuit further comprises:

a first timing circuit configured to divide the preset time range into ncounting cycles, where n is an integer greater than 1; and

a first determining circuit configured to determine whether the voltagevalue of the output signal in each of the counting cycles is greaterthan the first preset voltage threshold and determine that the voltagevalue of the output signal meets the preset over-voltage protectioncondition in the case that the voltage value of the output signal ineach of the counting cycles is greater than the first preset voltagethreshold.

In an embodiment, the voltage detection circuit comprises:

a second timing circuit configured to divide the preset time range inton counting cycles, where n is an integer greater than one; and

the second determining circuit configured to detect whether the voltagevalue of the output signal is greater than the first preset voltagethreshold in each of the counting cycles, count the counting cycles,output a count signal indicating the number of the counting cyclesduring which the voltage value of the output signal is greater than thefirst preset voltage threshold, and determine that the voltage value ofthe output signal meets the preset over-voltage protection condition inthe case that a value of the count signal is greater than a presetover-voltage period threshold.

In an embodiment, the over-voltage protection device is connected to asignal output circuit and configured to receive a voltage signal outputfrom the signal output circuit and the first control signal is furtherconfigured to control the signal output circuit to trigger anover-voltage protection operation.

In an embodiment, the over-voltage protection device further comprises:

a switch circuit configured to receive the output signal, and output asecond control signal in the case that the voltage value of the outputsignal is greater than or equal to a second preset voltage threshold tostop output of the output signal, wherein the second preset voltagethreshold is greater than the first preset voltage threshold.

In an embodiment of the present disclosure, it is provided a displaydevice, comprising:

a display panel;

a drive circuit; and

an over-voltage protection device;

wherein the drive circuit comprises a power management chip, and theover-voltage protection device is connected with the power managementchip;

wherein the over-voltage protection device comprises:

a voltage comparison circuit configured to determine whether a voltagevalue of an output signal is greater than a first preset voltagethreshold;

a voltage detection circuit configured to detect, within a present timerange, whether the voltage value of the output signal meets a presetover-voltage protection condition in the case that the voltage value ofthe output signal is greater than the first preset voltage threshold;and

a control circuit configured to output a first control signal to stopoutput of the output signal or to lower the voltage value of the outputsignal in the case that it is detected, within the preset time range,that the voltage value of the output signal meets the presetover-voltage protection condition.

In the overvoltage protection method, the overvoltage protection device,and the display device according to the present disclosure, whether avoltage value of an output signal is greater than a first preset voltagethreshold is determined, whether the voltage value of the output signalmeets a preset over-voltage protection condition is detected within apreset time range if the voltage value of the output signal is greaterthan the first preset voltage threshold, and a first control signal tostop output of the output signal or to lower the voltage value of theoutput signal is output if it is detected, within the preset time range,that the voltage value of the output signal meets the presetover-voltage protection condition, so that the output signal will not beimmediately stopped when the voltage value of the output signal isgreater than the first preset voltage threshold. The output signal isstopped or lowered only when it is detected, within the preset timerange that the voltage value of the output signal meets the presetover-voltage protection condition. Therefore, the problem in theexisting over-voltage protection, that is, the voltage output is usuallyturned off after the output voltage exceeds the threshold voltage, andthe false shutdown due to external noise interference cannot be avoided,which greatly affects the stability of the back-end circuit, can besolved.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in theembodiments of the present disclosure, the drawings used in theembodiments or the prior art description will be briefly describedbelow. It is obvious that the drawings in the following description areonly some embodiments of the present disclosure. To those skilled in theart, other drawings may be obtained from these drawings without payingany creative effort.

FIG. 1 is a schematic flow chart of an over-voltage protection methodaccording to an embodiment of the present disclosure;

FIG. 2 is a schematic flow chart of an over-voltage protection methodaccording to another embodiment of the present disclosure;

FIG. 3 is a schematic flow chart of an over-voltage protection methodaccording to another embodiment of the present disclosure;

FIG. 4 is a schematic flow chart of an over-voltage protection methodaccording to another embodiment of the present disclosure;

FIG. 5 is a schematic diagram of an over-voltage protection deviceaccording to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure;

FIG. 7 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure; and

FIG. 8 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

The technical solutions in the embodiments of the present disclosurewill be clearly described in the following with reference to theaccompanying drawings in the embodiments of the present disclosure. Itis obvious that the embodiments to be described are just some instead ofall embodiments of the present disclosure. All other embodimentsobtained by those skilled in the art based on the embodiments of thepresent disclosure without paying any creative effort should be includedwithin the protection scope of the present disclosure.

The term “comprise” and its variations in the specification, claims andabove description of the drawings of the present disclosure are intendedto cover non-exclusive inclusions. For example, a process, method orsystem, product or device including a series of steps or units is notlimited to the listed steps or units, but optionally also includes stepsor units not listed, or optionally also includes other steps or unitsinherent to the process, method, product or equipment. Moreover, theterms “first”, “second” and “third,” etc. are used to distinguishdifferent objects, and are not intended to describe a particular order.

A display panel usually needs different power supply voltages accordingto various functions of the function circuits. These power supplyvoltages may be provided by A power management chip. In order to preventthe voltage output signal output from the power management chip frombeing too large, an over-current protection mechanism is arranged insidethe power management chip. For example, a thin film transistor liquidcrystal display panel requires a plurality of voltage signals withdifferent voltage values. In order to provide a plurality of voltagesignals for the thin film transistor liquid crystal display panel, apower management chip is usually used to provide different voltageoutput signals. In order to prevent excessive voltage output signaloutput from the power management chip from burning the thin filmtransistor liquid crystal display panel, an over-current protectionmechanism is arranged inside the power management chip.

FIG. 1 is a schematic flow chart of an over-voltage protection methodaccording to an embodiment of the present disclosure.

As shown in FIG. 1, the over-voltage protection method in thisembodiment includes S11 to S13 as follows.

In S11, whether a voltage value of an output signal is greater than afirst preset voltage threshold is determined.

In an embodiment, the voltage value of the output signal is obtained.Specifically, the output signal in this embodiment is an output signalof a voltage output circuit, and the voltage output circuit may includea voltage management chip. The output signal from a voltage outputterminal is converted into a voltage value, and the voltage value iscompared with a preset first preset voltage threshold so that amagnitude relationship between the voltage value and the preset firstpreset voltage threshold is determined.

In an embodiment, the first preset voltage threshold may be a safetythreshold of the voltage signal output from the voltage output circuit,that is, when the voltage value of the voltage signal outputting fromthe voltage output circuit is greater than the safety threshold, thevoltage output circuit may be burned. Specifically, the safety thresholdmay be determined according to the specific use environment or the modelof the voltage output circuit.

In S12, whether the voltage value of the output signal meets a presetover-voltage protection condition is detected within a preset time rangein the case that the voltage value of the output signal is greater thanthe first preset voltage threshold.

In an embodiment, the voltage value of the output signal is detected,and the voltage value of the output signal is compared with the presetfirst preset voltage threshold. If the detected voltage value of theoutput signal is greater than the preset first preset voltage threshold,the voltage output signal is continuously detected within a preset timerange after the voltage value of the output signal is detected to begreater than the preset first preset voltage threshold, so as todetermine whether the voltage value of the output signal output meetsthe preset over-voltage protection condition within the preset timerange. Specifically, the preset time range is a period of time after thevoltage value of the output signal is greater than the first presetvoltage threshold, that is, the period of time between the start of thetiming and the end of the timing, where the timing starts when thevoltage value of the output signal is detected to be greater than thefirst preset voltage threshold. The period of time between the start ofthe timing and the end of the timing is set according to the user'sneeds. For example, when the voltage value of the output signal isdetected to be greater than the first preset voltage threshold, it isdetermined that the output signal is in an over-voltage state, thetiming is started at this time, and the voltage value of the outputsignal is continuously detected within 5 seconds from the start of thetiming so as to determine whether the voltage value of the output signalis always in an over-voltage state within 5 seconds from the start ofthe timing.

In an embodiment, the preset over-voltage protection condition may beset according to a user's needs. For example, the preset over-voltageprotection condition is the voltage value of the output signal riseswithin the preset time range, and the rising may be continuously.

In an embodiment, the preset over-voltage protection condition is thatthe voltage value of the output signal rises linearly within the presettime range. If the voltage value of the output signal within the presettime range continuously rises, it can be determined that the voltagevalue of the output signal within the preset time range meets the presetover-voltage protection condition.

In an embodiment, the preset over-voltage condition is that the voltagevalue of the output signal within the preset time range is greater thanthe first preset voltage threshold all the time and remains unchanged,then it is determined that the voltage value of the output signal withinthe preset time range meets the preset over-voltage protectioncondition.

In an embodiment, when the voltage value of the output signal is lessthan or equal to the first preset voltage threshold, the output signalis normally output.

In an embodiment, the output signal is sampled at a preset timeinterval, and the voltage value of the output signal is detected. Thevoltage value is compared with the first preset voltage threshold. Ifthe voltage value of the output signal is less than or equal to thefirst preset voltage threshold, the output signal is normally output,and the voltage value of the output signal is continuously sampled anddetermined at the preset time interval, and the process of sampling anddetermining the voltage value of the output signal has no effect on theoutput of the output signal. Only when the voltage value of the outputsignal is greater than the first preset voltage threshold, the nextstep, that is, determining whether the voltage value of the outputsignal meets the preset over-voltage protection condition within thepreset time range after the voltage value of the output signal isgreater than the first preset voltage threshold, is performed. Inparticular, the voltage value of the output signal is continuouslysampled and determined within the preset time range after the voltagevalue of the output signal is greater than the first preset voltagethreshold, and whether the continuously sampled voltage value meets thepreset over-voltage protection condition is determined.

In S13, a first control signal to stop output of the output signal or tolower the voltage value of the output signal is output in the case thatit is detected, within the preset time range, that the voltage value ofthe output signal meets the preset over-voltage protection condition.

In an embodiment, the voltage value of the output signal is continuouslydetected within the preset time range after the voltage value of theoutput signal is greater than the first preset voltage threshold. Thedetection process includes sampling the voltage value of the outputsignal and determining the magnitude relationship between the voltagevalue of the output signal and the first preset voltage threshold. Theoutput signal includes a voltage output signal. By continuously samplingthe voltage value of the output sign within the preset time range, aplurality of voltage values can be obtained, and whether the pluralityof voltage values meet the preset over-voltage protection condition isdetermined. If the plurality of voltage values meet the presetover-voltage protection condition the first control signal is output.The first control signal is configured to stop output of the outputsignal or lower the voltage value of the voltage output signal.

For example, if the preset over-voltage protection condition is that thevoltage value of the output signal continuously rises within the presettime range, it is determined whether the plurality of voltage valuesdetected within the preset time range continuously rises over time isdetermined. If the plurality of voltage values continuously rise overtime within the preset time range, it is determined that the pluralityof voltage values meet the preset over-voltage protection condition, andthe first control signal is output so as to stop output of the outputsignal or lower the voltage value of the output signal. Specifically,the mode of the control of the first control signal to the voltageoutput signal can be selected according to user's need.

In an embodiment, the preset over-voltage protection condition may bethat the voltage value of the output signal remains unchanged within THEpreset time range and is greater than the first preset voltagethreshold. And the determination for the plurality of voltage valuesdetected within the preset time range is performed to determine whetherthe plurality of voltage values are the same and greater than the firstpreset voltage threshold. If the plurality of voltage values detectedwithin the preset time range are the same and greater than the firstpreset voltage threshold, the first control signal is output to controland adjust the output signal.

FIG. 2 is a schematic flow chart of an over-voltage protection methodaccording to another embodiment of the present disclosure.

In this embodiment, detecting, within the present time range, whetherthe voltage value of the output signal meets the preset over-voltageprotection condition in the case that the voltage value of the outputsignal is greater than the first preset voltage threshold isspecialized. As shown in FIG. 2, the step of detecting, within a presenttime range, whether the voltage value of the output signal meets apreset over-voltage protection condition in the case that the voltagevalue of the output signal is greater than the first preset voltagethreshold includes S21 to S23 as follows.

In S21, the preset time range is divided into n counting cycles, where nis an integer greater than 1.

In an embodiment, the timing is started since the voltage value of theoutput signal is greater than the first preset voltage threshold, andthe preset time range from the start of the timing is divided into ncounting cycles, where n is an integer greater than 1. For example,according to the user's need the preset time range is set to be 10seconds, and the 10 seconds after the start of the timing when thevoltage value of the output signal is greater than the first presetvoltage threshold is divided into 10 counting cycles, each countingcycle being 1 second.

In S22, it is determined whether the voltage value of the output signalin each of the counting cycles is greater than the first preset voltagethreshold.

In an embodiment, the voltage value of the output signal in eachcounting cycle is sampled and the magnitude relationship between thevoltage value and the first preset voltage threshold is compared. Forexample, if the preset time range is set to 10 seconds, and the 10seconds after the start of the timing when the voltage value of theoutput signal is greater than the first preset voltage threshold isdivided into 10 counting cycles, where each counting cycle is 1 second,then the voltage value of the output signal is sampled once in eachcounting cycle of 1 second, and the voltage value sampled in each timingperiod is compared with the first preset voltage threshold to obtain acomparison result. As a result, 10 comparison results are obtained andwhether the voltage values of the output signal, among the 10 comparisonresults, are greater than the first preset voltage threshold isdetermined.

In S23, it is determined that the voltage value of the output signalmeets the preset over-voltage protection condition in the case that thevoltage value of the output signal in each counting cycle is greaterthan the first preset voltage threshold.

In an embodiment, the preset over-voltage protection condition in thisembodiment is that the voltage value of the output signal sampled ineach counting cycle is greater than the first preset voltage threshold.Specifically, the comparison result detected in each timing period isdetermined. If the voltage value of the output signal is greater thanthe first preset voltage threshold in each timing cycle, it isdetermined that the voltage value of the output signal meets the presetover-voltage protection conditions.

FIG. 3 is a schematic flow chart of an over-voltage protection methodaccording to another embodiment of the present disclosure.

In this embodiment, the step of detecting, within the present timerange, whether the voltage value of the output signal meets the presetover-voltage protection condition in the case that the voltage value ofthe output signal is greater than the first preset voltage threshold isspecialized. As shown in FIG. 3, the step of detecting, within a presenttime range, whether the voltage value of the output signal meets apreset over-voltage protection condition, in the case that the voltagevalue of the output signal is greater than the first preset voltagethreshold includes S31 to S33 as follows.

In S31, the preset time range is divided into n counting cycles, where nis an integer greater than 1.

In S32, it is detected whether the voltage value of the output signal isgreater than the first preset voltage threshold in each counting cycle.

In S33, the counting cycles are counted and a count signal indicatingthe number of the counting cycles during which the voltage value of theoutput signal is greater than the first preset voltage threshold isoutput.

In an embodiment, the timing is started since the voltage value of theoutput signal is greater than the first preset voltage threshold, andthe preset time range from the start of the timing is divided into ncounting cycles, where n is an integer greater than 1. The voltage valueof the output signal is sampled once in each of the n counting cycles,and the voltage value sampled in each counting cycle is compared withthe first preset voltage threshold so that a comparison result isobtained. Then, the comparison results obtained by the detection iscounted, and a count signal is output, the count signal indicating thenumber of the counting cycles during which the voltage value is greaterthan the first preset voltage threshold in n counting cycles. Forexample, if the preset time range is set to 10 seconds according to theuser's need, and the 10 seconds after starting the timing from the timewhen the voltage value of the output signal is greater than the firstpreset voltage threshold is divided into 10 counting cycles, where eachcounting cycle is 1 second. Comparing the voltage value of the outputsignal in each timing cycle with the first preset voltage threshold canobtain 10 comparison results. And then the number of comparison results,among the 10 comparison results, in which the voltage value of theoutput signal is greater than the first preset voltage threshold isdetermined. For example, if, among the 10 comparison results, only thevoltage value of the output signal in 9 timing cycles is greater thanthe first preset voltage threshold, a corresponding count signal isoutput.

In S34, it is determined that the voltage value of the output signalmeets the preset over-voltage protection condition in the case that thevalue of the count signal is greater than a preset over-voltage periodthreshold.

In an embodiment, the value of the count signal is compared with apreset over-voltage period threshold, and the voltage value of theoutput signal is determined to meet a preset over-voltage protectioncondition. Specifically, the preset over-voltage protection condition inthis embodiment is that when the value of the count signal is greaterthan the preset over-voltage period threshold, it is determined that thevoltage value of the output signal meets the preset over-voltageprotection condition within the preset time range. Specifically, thepreset over-voltage period threshold is set by the user and configuredto be a critical safety threshold for determining the number of cyclesin which the voltage value of the output signal is greater than thepreset voltage threshold in the n counting cycles, that is, if, in nperiods, the number of cycles in which the voltage value of the outputsignal is greater than the preset voltage threshold, it is determinedthat the voltage value of the output signal meets the presetover-voltage protection condition. For example, if in this embodimentthe preset over-voltage period threshold is 8, if the voltage value ofthe output signal in 9 timing cycles, among the n cycles, is greaterthan the first preset voltage threshold, the value of the timing signalis greater than the preset over-voltage period threshold, it istherefore determined that the voltage value of the output signal meetsthe preset over-voltage protection condition within the preset timerange, so as to avoid the detection error caused by the instantaneousfluctuation of the output signal within the preset time range from thetime when the voltage value of the output signal is greater than thefirst preset voltage threshold.

In an embodiment, the output signal in this embodiment is a voltagesignal output from a signal output circuit, and the first control signalis further configured to control the signal output circuit to trigger anover-voltage protection operation.

In an embodiment, the signal output circuit is internally provided withan over-voltage protection mechanism, and after receiving the triggersignal, the over-voltage protection mechanism is triggered to turn offthe output of the voltage signal. The timing is started when the voltagevalue of the output signal is greater than the first preset voltagethreshold. And if the voltage value of the output signal detected withinthe preset time range after the start of the timing meets the presetover-voltage protection condition the first control signal is output tothe signal output circuit, and the first control signal can be used asthe trigger signal to trigger the output circuit to initiate theover-voltage protection mechanism. Specifically, the signal outputcircuit may be a power management chip.

FIG. 4 is a schematic flow chart of an over-voltage protection methodaccording to another embodiment of the present disclosure.

As shown in FIG. 4, the over-voltage protection method in thisembodiment further includes:

receiving the output signal, and outputting the second control signal inthe case that the voltage value of the output signal is greater than orequal to the second preset voltage threshold to stop output of theoutput signal, where the second preset voltage threshold is greater thanthe first preset voltage threshold.

In an embodiment, the output signal is received and the voltage value ofthe output signal is detected. The detection process includes a samplingprocess and a determination process. When the voltage value of theoutput signal is sampled, the voltage value is compared with the presetsecond preset voltage threshold. If the voltage value is greater than orequal to the second preset voltage threshold, the second control signalis output to stop output of the output signal, where the second presetvoltage threshold is greater than the first preset voltage threshold.Thus it is avoided that when the output signal is beyond the toleranceof the back-end circuit, the voltage value of the output signal is stilldetected within the preset time range after the voltage value of theoutput signal is greater than the first preset voltage threshold, whichcauses the back-end circuit to burn out because the output signal cannotbe turned off in time.

FIG. 5 is a schematic diagram of an over-voltage protection deviceaccording to an embodiment of the present disclosure.

As shown in FIG. 5, the over-voltage protection device in thisembodiment includes a voltage comparison circuit 10, a voltage detectioncircuit 20 and a control circuit 30.

The voltage comparison circuit 10 is configured to determine whether avoltage value of an output signal is greater than a first preset voltagethreshold.

The voltage detection circuit 20 is configured to detect, within apreset time range, whether the voltage value of the output signal meetsa preset over-voltage protection condition in the case that the voltagevalue of the output signal is greater than the first preset voltagethreshold.

The control circuit 30 is configured to output a first control signal tostop output of the output signal or to lower the voltage value of theoutput signal in the case that it is detected, within the preset timerange, that the voltage value of the output signal meets the presetover-voltage protection condition.

In one embodiment, the voltage comparison circuit 10 detects the voltagevalue of the output signal. Specifically, the output signal of thevoltage output terminal is converted into a voltage value, and thevoltage value is compared with a preset first preset voltage thresholdto determine a magnitude relationship between the voltage value and thepreset first preset voltage threshold.

The voltage detection circuit 20 detects whether the voltage value ofthe output signal meets the preset over-voltage protection condition.Specifically, the voltage value of the output signal is detected, andthe voltage value of the output signal is compared with the preset firstpreset voltage threshold. If the detected voltage value of the outputsignal is greater than the preset first preset voltage threshold, thevoltage output signal is continuously detected within a preset timerange after the voltage value of the output signal is detected to begreater than the preset first preset voltage threshold, so as todetermine whether the voltage value of the output signal output meetsthe preset over-voltage protection condition within the preset timerange. The preset over-voltage protection condition may be set accordingto user's need. For example, the preset over-voltage protectioncondition is the voltage value of the output signal continuously risesor rises linearly within the preset time range. If the voltage value ofthe output signal continuously rises within the preset time range, itcan be determined that the voltage value of the output signal within thepreset time range meets the preset over-voltage protection condition. Orthe preset over-voltage condition is that the voltage value of theoutput signal within the preset time range is greater than the firstpreset power threshold all the time and remains unchanged, then it isdetermined that the voltage value of the output signal within the presettime range meets the preset over-voltage protection condition.

In an embodiment, when the voltage value of the output signal detectedby the voltage comparison circuit 10 is less than or equal to the firstpreset voltage threshold, the output signal is normally output.Specifically, the voltage comparison circuit 10 samples the outputsignal at a preset time interval and detects the voltage value of theoutput signal. The voltage value is compared with the first presetvoltage threshold. If the voltage value of the output signal is lessthan or equal to the first preset voltage threshold, the output signalis normally output, and the voltage value of the output signal iscontinuously sampled and determined at the preset time interval, and theprocess of sampling and determining the voltage value of the outputsignal has no effect on the output of the output signal. Only when thevoltage value of the output signal is greater than the first presetvoltage threshold, the next step, that is, determining whether thevoltage value of the output signal meets the preset over-voltageprotection condition within the preset time range after the voltagevalue of the output signal is greater than the first preset voltagethreshold, is performed. In particular, the voltage value of the outputsignal is continuously sampled and determined within the preset timerange after the voltage value of the output signal is greater than thefirst preset voltage threshold, and whether the continuously sampledvoltage value meets the preset over-voltage protection condition isdetermined.

In an embodiment, when the control circuit 30 outputs a first controlsignal to stop output of the output signal or to lower the voltage valueof the output signal in the case that it is detected, within the presettime range, that the voltage value of the output signal meets the presetover-voltage protection condition.

In an embodiment, the voltage value of the output signal is continuouslydetected within the preset time range after the voltage value of theoutput signal is greater than the first preset voltage threshold. Thedetection process includes sampling the voltage value of the outputsignal and determining the magnitude relationship between the voltagevalue of the output signal and the first preset voltage threshold. Theoutput signal includes a voltage output signal. By continuously samplingthe voltage value of the output sign within the preset time range, aplurality of voltage values can be obtained, and whether the pluralityof voltage values meet the preset over-voltage protection condition isdetermined. If the plurality of voltage values meet the presetover-voltage protection condition the first control signal is output.The first control signal is configured to stop output of the outputsignal or lower the voltage value of the voltage output signal.

For example, if the preset over-voltage protection condition is that thevoltage value of the output signal continuously rises within the presettime range, it is determined whether the plurality of voltage valuesdetected within the preset time range continuously rises over time isdetermined. If the plurality of voltage values continuously rise overtime within the preset time range, it is determined that the pluralityof voltage values meet the preset over-voltage protection condition, andthe first control signal is output so as to stop output of the outputsignal or lower the voltage value of the output signal. Specifically,the mode of the control of the first control signal to the voltageoutput signal can be selected according to user's need. In anembodiment, the preset over-voltage protection condition may be that thevoltage value of the output signal remains unchanged within THE presettime range and is greater than the first preset voltage threshold. Andthe determination for the plurality of voltage values detected withinthe preset time range is performed to determine whether the plurality ofvoltage values are the same and greater than the first preset voltagethreshold. If the plurality of voltage values detected within the presettime range are the same and greater than the first preset voltagethreshold, the first control signal is output to control and adjust theoutput signal.

FIG. 6 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure.

As shown in FIG. 6, the voltage detection circuit 20 includes a firsttiming circuit 211 and a first determining circuit 212.

The first timing circuit 211 is configured to divide the preset timerange into n counting cycles, where n is an integer greater than one.

The first determining circuit 212 is configured to determine whether thevoltage value of the output signal in each of the counting cycles isgreater than the first preset voltage threshold and determine that thevoltage value of the output signal meets the preset over-voltageprotection condition in the case that the voltage value of the outputsignal in each counting cycle is greater than the first preset voltagethreshold.

In an embodiment, the first timing circuit 211 starts the timing sincethe voltage value of the output signal is greater than the first presetvoltage threshold, and the preset time range from the start of thetiming is divided into n counting cycles, where n is an integer greaterthan 1. For example, according to the user's need the preset time rangeis set to be 10 seconds, and the 10 seconds after the start of thetiming when the voltage value of the output signal is greater than thefirst preset voltage threshold is divided into 10 counting cycles, eachcounting cycle being 1 second. The first determining circuit 212 samplesthe voltage value of the output signal in each counting cycle andcompares the magnitude relationship between the voltage value and thefirst preset voltage threshold. For example, if the preset time range isset to 10 seconds, and the 10 seconds after the start of the timing whenthe voltage value of the output signal is greater than the first presetvoltage threshold is divided into 10 counting cycles, where eachcounting cycle is 1 second, then the voltage value of the output signalis sampled once in each counting cycle of 1 second, and the voltagevalue sampled in each timing period is compared with the first presetvoltage threshold to obtain a comparison result. As a result, 10comparison results are obtained and whether the voltage values of theoutput signal, among the 10 comparison results, are greater than thefirst preset voltage threshold is determined.

In an embodiment, the preset over-voltage protection condition in thisembodiment is that the voltage value of the output signal sampled ineach counting cycle is greater than the first preset voltage threshold.Specifically, the comparison result detected in each timing period isdetermined. If the voltage value of the output signal is greater thanthe first preset voltage threshold in each timing cycle, it isdetermined that the voltage value of the output signal meets the presetover-voltage protection conditions.

FIG. 7 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure.

As shown in FIG. 7, the voltage detection circuit 20 includes a secondtiming circuit 221 and a second determining circuit 222.

The second timing circuit 221 is configured to divide the preset timerange into n counting cycles, where n is an integer greater than 1.

The second determining circuit 222 is configured to detect whether thevoltage value of the output signal is greater than the first presetvoltage threshold in each counting cycle, count the counting cycles,output a count signal indicating the number of the counting cyclesduring which the voltage value of the output signal is greater than thefirst preset voltage threshold, and determines that the voltage value ofthe output signal meets the preset over-voltage protection condition inthe case that the value of the count signal is greater than a presetover-voltage period threshold.

In one embodiment, the second timing circuit 221 the timing is startedsince the voltage value of the output signal is greater than the firstpreset voltage threshold, and the preset time range from the start ofthe timing is divided into n counting cycles, where n is an integergreater than 1. The voltage value of the output signal is sampled oncein each of the n counting cycles, and the voltage value sampled in eachcounting cycle is compared with the first preset voltage threshold sothat a comparison result is obtained. Then, the comparison resultsobtained by the detection is counted, and a count signal is output, thecount signal indicating the number of the counting cycles during whichthe voltage value is greater than the first preset voltage threshold inn counting cycles. For example, if the preset time range is set to 10seconds according to the user's need, and the 10 seconds after startingthe timing from the time when the voltage value of the output signal isgreater than the first preset voltage threshold is divided into 10counting cycles, where each counting cycle is 1 second. Comparing thevoltage value of the output signal in each timing cycle with the firstpreset voltage threshold can obtain 10 comparison results. And then thenumber of comparison results, among the 10 comparison results, in whichthe voltage value of the output signal is greater than the first presetvoltage threshold is determined. For example, if among the 10 comparisonresults, only the voltage value of the output signal in 9 timing cyclesis greater than the first preset voltage threshold, a correspondingcount signal is output. The second determining circuit 222 compares thevalue of the count signal with a preset over-voltage period threshold,and determines the voltage value of the output signal meets a presetover-voltage protection condition. Specifically, the preset over-voltageprotection condition in this embodiment is that when the value of thecount signal is greater than the preset over-voltage period threshold,it is determined that the voltage value of the output signal meets thepreset over-voltage protection condition within the preset time range.For example, if in this embodiment the preset over-voltage periodthreshold is 8, if the voltage value of the output signal in 9 timingcycles is greater than the first preset voltage threshold, the value ofthe timing signal is greater than the preset over-voltage periodthreshold, it is therefore determined that the voltage value of theoutput signal meets the preset over-voltage protection condition withinthe preset time range, so as to avoid the detection error caused by theinstantaneous fluctuation of the output signal within the preset timerange from the time when the voltage value of the output signal isgreater than the first preset voltage threshold.

In an embodiment, the over-voltage protection device is connected to thesignal output circuit and configured to receive the voltage signaloutput from the signal output circuit and the first control signal isfurther configured to control the signal output circuit to trigger theover-voltage protection operation.

In an embodiment, the signal output circuit is configured to output avoltage signal, i.e., the output signal described in the aboveembodiments. In an embodiment, the signal output circuit may be a powermanagement chip.

FIG. 8 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure.

As shown in FIG. 8, the over-voltage protection device further includesa switch circuit 40.

The switch circuit 40 is configured to receive the output signal, andoutput the second control signal if the voltage value of the outputsignal is greater than or equal to the second preset voltage thresholdto stop output of the output signal, where the second preset voltagethreshold is greater than the first preset voltage threshold.

In an embodiment, the switch circuit 40 receives the output signal anddetects the voltage value of the output signal. The detection processincludes a sampling process and a determination process. When thevoltage value of the output signal is sampled, the voltage value iscompared with the preset second preset voltage threshold. If the voltagevalue is greater than or equal to the second preset voltage threshold,the second control signal is output to stop output of the output signal,where the second preset voltage threshold is greater than the firstpreset voltage threshold. Thus it is avoided that when the output signalis beyond the tolerance of the back-end circuit, the voltage value ofthe output signal is still detected within the preset time range afterthe voltage value of the output signal is greater than the first presetvoltage threshold, which causes the back-end circuit to burn out becausethe output signal cannot be turned off in time.

In an embodiment of the present disclosure, it is provided a displaydevice, includes a display panel, a drive circuit and an over-voltageprotection device.

The drive circuit includes a power management chip, and the over-voltageprotection device is connected to the power management chip.

The over-voltage protection device includes a voltage comparison circuit10, a voltage detection circuit 20 and a control circuit 30.

The voltage comparison circuit 10 is configured to determine whether avoltage value of an output signal is greater than a first preset voltagethreshold.

The voltage detection circuit 20 is configured to detect, within apreset time range, whether the voltage value of the output signal meetsa preset over-voltage protection condition in the case that the voltagevalue of the output signal is greater than the first preset voltagethreshold.

The control circuit 30 is configured to output a first control signal tostop output of the output signal or to lower the voltage value of theoutput signal in the case that it is detected, within the preset timerange, that the voltage value of the output signal meets the presetover-voltage protection condition.

In an embodiment, the display device may be any type of display deviceprovided with the above-mentioned over-voltage protection device, suchas a liquid crystal display (LCD), an organic electroluminescencedisplay (OLED) device, a quantum dot light emitting diodes (QLED)display device or a curved display device.

In an embodiment, the display panel includes a pixel array consisting ofa plurality of rows of pixels and a plurality of columns of pixels.

In an embodiment, the voltage comparison circuit 10 detects the voltagevalue of the output signal. Specifically, the output signal of thevoltage output terminal is converted into a voltage value, and thevoltage value is compared with a preset first preset voltage thresholdto determine a magnitude relationship between the voltage value and thepreset first preset voltage threshold.

The voltage detection circuit 20 detects whether the voltage value ofthe output signal meets the preset over-voltage protection condition.Specifically, the voltage value of the output signal is detected, andthe voltage value of the output signal is compared with the preset firstpreset voltage threshold. If the detected voltage value of the outputsignal is greater than the preset first preset voltage threshold, thevoltage output signal is continuously detected within a preset timerange after the voltage value of the output signal is detected to begreater than the preset first preset voltage threshold, so as todetermine whether the voltage value of the output signal output meetsthe preset over-voltage protection condition within the preset timerange. The preset over-voltage protection condition may be set accordingto user's need. For example, the preset over-voltage protectioncondition is the voltage value of the output signal continuously risesor rises linearly within the preset time range. If the voltage value ofthe output signal continuously rises within the preset time range, itcan be determined that the voltage value of the output signal within thepreset time range meets the preset over-voltage protection condition. Orthe preset over-voltage condition is that the voltage value of theoutput signal within the preset time range is greater than the firstpreset power threshold all the time and remains unchanged, then it isdetermined that the voltage value of the output signal within the presettime range meets the preset over-voltage protection condition.

In an embodiment, when the voltage value of the output signal detectedby the voltage comparison circuit 10 is less than or equal to the firstpreset voltage threshold, the output signal is normally output.Specifically, the voltage comparison circuit 10 samples the outputsignal at a preset time interval and detects the voltage value of theoutput signal. The voltage value is compared with the first presetvoltage threshold. If the voltage value of the output signal is lessthan or equal to the first preset voltage threshold, the output signalis normally output, and the voltage value of the output signal iscontinuously sampled and determined at the preset time interval, and theprocess of sampling and determining the voltage value of the outputsignal has no effect on the output of the output signal. Only when thevoltage value of the output signal is greater than the first presetvoltage threshold, the next step, that is, determining whether thevoltage value of the output signal meets the preset over-voltageprotection condition within the preset time range after the voltagevalue of the output signal is greater than the first preset voltagethreshold, is performed. In particular, the voltage value of the outputsignal is continuously sampled and determined within the preset timerange after the voltage value of the output signal is greater than thefirst preset voltage threshold, and whether the continuously sampledvoltage value meets the preset over-voltage protection condition isdetermined.

In an embodiment, when the control circuit 30 outputs a first controlsignal to stop output of the output signal or to lower the voltage valueof the output signal in the case that it is detected, within the presettime range, that the voltage value of the output signal meets the presetover-voltage protection condition.

In an embodiment, the voltage value of the output signal is continuouslydetected within the preset time range after the voltage value of theoutput signal is greater than the first preset voltage threshold. Thedetection process includes sampling the voltage value of the outputsignal and determining the magnitude relationship between the voltagevalue of the output signal and the first preset voltage threshold. Theoutput signal includes a voltage output signal. By continuously samplingthe voltage value of the output sign within the preset time range, aplurality of voltage values can be obtained, and whether the pluralityof voltage values meet the preset over-voltage protection condition isdetermined. If the plurality of voltage values meet the presetover-voltage protection condition the first control signal is output.The first control signal is configured to stop output of the outputsignal or lower the voltage value of the voltage output signal.

For example, if the preset over-voltage protection condition is that thevoltage value of the output signal continuously rises within the presettime range, it is determined whether the plurality of voltage valuesdetected within the preset time range continuously rises over time isdetermined. If the plurality of voltage values continuously rise overtime within the preset time range, it is determined that the pluralityof voltage values meet the preset over-voltage protection condition, andthe first control signal is output so as to stop output of the outputsignal or lower the voltage value of the output signal. Specifically,the mode of the control of the first control signal to the voltageoutput signal can be selected according to user's need. In anembodiment, the preset over-voltage protection condition may be that thevoltage value of the output signal remains unchanged within THE presettime range and is greater than the first preset voltage threshold. Andthe determination for the plurality of voltage values detected withinthe preset time range is performed to determine whether the plurality ofvoltage values are the same and greater than the first preset voltagethreshold. If the plurality of voltage values detected within the presettime range are the same and greater than the first preset voltagethreshold, the first control signal is output to control and adjust theoutput signal.

FIG. 6 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure.

As shown in FIG. 6, the voltage detection circuit 20 includes a firsttiming circuit 211 and a first determining circuit 212.

The first timing circuit 211 is configured to divide the preset timerange into n counting cycles, where n is an integer greater than one.

The first determining circuit 212 is configured to determine whether thevoltage value of the output signal in each of the counting cycles isgreater than the first preset voltage threshold and determine that thevoltage value of the output signal meets the preset over-voltageprotection condition in the case that the voltage value of the outputsignal in each counting cycle is greater than the first preset voltagethreshold.

In an embodiment, the first timing circuit 211 starts the timing sincethe voltage value of the output signal is greater than the first presetvoltage threshold, and the preset time range from the start of thetiming is divided into n counting cycles, where n is an integer greaterthan 1. For example, according to the user's need the preset time rangeis set to be 10 seconds, and the 10 seconds after the start of thetiming when the voltage value of the output signal is greater than thefirst preset voltage threshold is divided into 10 counting cycles, eachcounting cycle being 1 second. The first determining circuit 212 samplesthe voltage value of the output signal in each counting cycle andcompares the magnitude relationship between the voltage value and thefirst preset voltage threshold. For example, if the preset time range isset to 10 seconds, and the 10 seconds after the start of the timing whenthe voltage value of the output signal is greater than the first presetvoltage threshold is divided into 10 counting cycles, where eachcounting cycle is 1 second, then the voltage value of the output signalis sampled once in each counting cycle of 1 second, and the voltagevalue sampled in each timing period is compared with the first presetvoltage threshold to obtain a comparison result. As a result, 10comparison results are obtained and whether the voltage values of theoutput signal, among the 10 comparison results, are greater than thefirst preset voltage threshold is determined.

In an embodiment, the preset over-voltage protection condition in thisembodiment is that the voltage value of the output signal sampled ineach counting cycle is greater than the first preset voltage threshold.Specifically, the comparison result detected in each timing period isdetermined. If the voltage value of the output signal is greater thanthe first preset voltage threshold in each timing cycle, it isdetermined that the voltage value of the output signal meets the presetover-voltage protection conditions.

FIG. 7 is a schematic diagram of an over-voltage protection deviceaccording to another embodiment of the present disclosure.

As shown in FIG. 7, the voltage detection circuit 20 includes a secondtiming circuit 221 and a second determining circuit 222.

The second timing circuit 221 is configured to divide the preset timerange into n counting cycles, where n is an integer greater than 1.

The second determining circuit 222 is configured to detect whether thevoltage value of the output signal is greater than the first presetvoltage threshold in each counting cycle, count the counting cycles,output a count signal indicating the number of the counting cyclesduring which the voltage value of the output signal is greater than thefirst preset voltage threshold, and determines that the voltage value ofthe output signal meets the preset over-voltage protection condition inthe case that the value of the count signal is greater than a presetover-voltage period threshold.

In one embodiment, the second timing circuit 221 the timing is startedsince the voltage value of the output signal is greater than the firstpreset voltage threshold, and the preset time range from the start ofthe timing is divided into n counting cycles, where n is an integergreater than 1. The voltage value of the output signal is sampled oncein each of the n counting cycles, and the voltage value sampled in eachcounting cycle is compared with the first preset voltage threshold sothat a comparison result is obtained. Then, the comparison resultsobtained by the detection is counted, and a count signal is output, thecount signal indicating the number of the counting cycles during whichthe voltage value is greater than the first preset voltage threshold inn counting cycles. For example, if the preset time range is set to 10seconds according to the user's need, and the 10 seconds after startingthe timing from the time when the voltage value of the output signal isgreater than the first preset voltage threshold is divided into 10counting cycles, where each counting cycle is 1 second. Comparing thevoltage value of the output signal in each timing cycle with the firstpreset voltage threshold can obtain 10 comparison results. And then thenumber of comparison results, among the 10 comparison results, in whichthe voltage value of the output signal is greater than the first presetvoltage threshold is determined. For example, if, among the 10comparison results, only the voltage value of the output signal in 9timing cycles is greater than the first preset voltage threshold, acorresponding count signal is output. The second determining circuit 222compares the value of the count signal with a preset over-voltage periodthreshold, and determines the voltage value of the output signal meets apreset over-voltage protection condition. Specifically, the presetover-voltage protection condition in this embodiment is that when thevalue of the count signal is greater than the preset over-voltage periodthreshold, it is determined that the voltage value of the output signalmeets the preset over-voltage protection condition within the presettime range. For example, if in this embodiment the preset over-voltageperiod threshold is 8, if the voltage value of the output signal in 9timing cycles is greater than the first preset voltage threshold, thevalue of the timing signal is greater than the preset over-voltageperiod threshold, it is therefore determined that the voltage value ofthe output signal meets the preset over-voltage protection conditionwithin the preset time range, so as to avoid the detection error causedby the instantaneous fluctuation of the output signal within the presettime range from the time when the voltage value of the output signal isgreater than the first preset voltage threshold.

In an embodiment, the over-voltage protection device is connected to thesignal output circuit and configured to receive the voltage signaloutput from the signal output circuit and the first control signal isfurther configured to control the signal output circuit to trigger theover-voltage protection operation.

In an embodiment, the circuit in the above described embodiments may bea central processing unit (CPU), or may be another general-purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field-programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logicdevice, discrete hardware component, etc.

In an embodiment, the general-purpose processor may be a microprocessoror the processor may be any conventional processor or the like.

The above descriptions are only optional embodiments of the presentdisclosure, and are not intended to limit the present disclosure. Anymodifications, equivalent substitutions and improvements made within thespirit and principles of the present disclosure are included in theprotection scope of the present disclosure.

What is claimed is:
 1. An over-voltage protection method, comprising:determining whether a voltage value of an output signal is greater thana first preset voltage threshold; detecting, within a present timerange, whether the voltage value of the output signal meets a presetover-voltage protection condition in the case that the voltage value ofthe output signal is greater than the first preset voltage threshold;and outputting a first control signal to stop output of the outputsignal or to lower the voltage value of the output signal in the casethat it is detected, within the preset time range, that the voltagevalue of the output signal meets the preset over-voltage protectioncondition; wherein the step of detecting, within a present time range,whether the voltage value of the output signal meets a presetover-voltage protection condition comprises: dividing the preset timerange into n counting cycles, where n is an integer greater than 1;determining whether the voltage value of the output signal in each ofthe counting cycles is greater than the first preset voltage threshold;and determining that the voltage value of the output signal meets thepreset over-voltage protection condition in the case that the voltagevalue of the output signal in each of the counting cycles is greaterthan the first preset voltage threshold.
 2. The over-voltage protectionmethod of claim 1, wherein the preset over-voltage protection conditioncomprises: the voltage value of the output signal rises during thepreset time range.
 3. The over-voltage protection method of claim 2,wherein the condition that the voltage value of the output signal risesduring the preset time range comprises: the voltage value of the outputsignal rises linearly during the preset time range.
 4. The over-voltageprotection method of claim 1, wherein the output signal is a voltagesignal output from a signal output circuit, and the first control signalis further configured to control the signal output circuit to trigger anover-voltage protection operation.
 5. The over-voltage protection methodof claim 4, wherein triggering an over-voltage protection operationcomprises: stopping the output of the output signal.
 6. The over-voltageprotection method of claim 1, wherein the preset over-voltage protectioncondition comprises: the voltage value of the output signal is greaterthan the first preset voltage threshold during the preset time range. 7.The over-voltage protection method of claim 1, wherein the over-voltageprotection method further comprises: receiving the output signal; andoutputting a second control signal in the case that the voltage value ofthe output signal is greater than or equal to a second preset voltagethreshold to stop output of the output signal, wherein the second presetvoltage threshold is greater than the first preset voltage threshold. 8.An over-voltage protection device, comprising: a voltage comparisoncircuit configured to determine whether a voltage value of an outputsignal is greater than a first preset voltage threshold; a voltagedetection circuit configured to detect, within a present time range,whether the voltage value of the output signal meets a presetover-voltage protection condition in the case that the voltage value ofthe output signal is greater than the first preset voltage threshold;and a control circuit configured to output a first control signal tostop output of the output signal or to lower the voltage value of theoutput signal in the case that it is detected, within the preset timerange, that the voltage value of the output signal meets the presetover-voltage protection condition; wherein the voltage detection circuitfurther comprises: a first timing circuit configured to divide thepreset time range into n counting cycles, where n is an integer greaterthan 1; and a first determining circuit configured to determine whetherthe voltage value of the output signal in each of the counting cycles isgreater than the first preset voltage threshold and determine that thevoltage value of the output signal meets the preset over-voltageprotection condition in the case that the voltage value of the outputsignal in each of the counting cycles is greater than the first presetvoltage threshold.
 9. The over-voltage protection device of claim 8,wherein the preset over-voltage protection condition comprises: thevoltage value of the output signal rises during the preset time range.10. The over-voltage protection device of claim 8, wherein the presetover-voltage protection condition comprises: the voltage value of theoutput signal rises linearly during the preset time range.
 11. Theover-voltage protection device of claim 8, wherein the presetover-voltage protection condition comprises: the voltage value of theoutput signal is greater than the first preset voltage threshold duringthe preset time range.
 12. The over-voltage protection device of claim8, wherein the over-voltage protection device further comprises: aswitch circuit configured to receive the output signal, and output asecond control signal in the case that the voltage value of the outputsignal is greater than or equal to a second preset voltage threshold tostop output of the output signal, wherein the second preset voltagethreshold is greater than the first preset voltage threshold.
 13. Theover-voltage protection device of claim 8, wherein the over-voltageprotection device is connected to a signal output circuit and configuredto receive a voltage signal output from the signal output circuit andthe first control signal is further configured to control the signaloutput circuit to trigger an over-voltage protection operation.
 14. Theover-voltage protection device of claim 13, wherein the first controlsignal is further configured to control the signal output circuit tostop output of the output signal.
 15. The over-voltage protection deviceof claim 13, wherein the signal output circuit is a power managementchip.
 16. A display device, comprising: a display panel; a drivecircuit; and an over-voltage protection device; wherein the drivecircuit comprises a power management chip, and the over-voltageprotection device is connected with the power management chip; whereinthe over-voltage protection device comprises: a voltage comparisoncircuit configured to determine whether a voltage value of an outputsignal is greater than a first preset voltage threshold; a voltagedetection circuit configured to detect, within a present time range,whether the voltage value of the output signal meets a presetover-voltage protection condition in the case that the voltage value ofthe output signal is greater than the first preset voltage threshold;and a control circuit configured to output a first control signal tostop output of the output signal or to lower the voltage value of theoutput signal in the case that it is detected, within the preset timerange, that the voltage value of the output signal meets the presetover-voltage protection condition; wherein the voltage detection circuitfurther comprises: a first timing circuit configured to divide thepreset time range into n counting cycles, where n is an integer greaterthan 1; and a first determining circuit configured to determine whetherthe voltage value of the output signal in each of the counting cycles isgreater than the first preset voltage threshold and determine that thevoltage value of the output signal meets the preset over-voltageprotection condition in the case that the voltage value of the outputsignal in each of the counting cycles is greater than the first presetvoltage threshold.